1. On the length of programs for computing finite binary sequences;Chaitin,1966
2. On the length of programs for computing finite binary sequences: statistical considerations;Chaitin;J. ACM,1969
3. Tri podhoda k opredeleniju ponjatija ‘količestvo informacii’;Kolmogorov;Problemy Peredači Informacii,1965
4. The definition of random sequences;Martin-Löf;Information and Control,1966
5. P. Martin-Löf, O kolebanii složnosti beskonečnykh dvoičnykh posledovatel'nostej, unpublished.